The power and cooling cost for large information technology (IT) infrastructures, such as data centers, can easily exceed millions of dollars per year. Yet, computing resources such as central processing units (CPUs), memory, network switches, etc. within each data center are being used at much less than maximum capacity. Consequently, a large percentage of the power and cooling costs are being consumed by “idle” computing resources, thereby wasting energy and driving up costs for IT infrastructures. As referred herein, and as understood in the art, information technology, or IT, encompasses all forms of technology, including but not limited to the design, development, installation, and implementation of hardware and software information systems and software applications, used to create, store, exchange and utilize information in its various forms including but not limited to business data, conversations, still images, motion pictures and multimedia presentations technology and with the design, development, installation, and implementation of information systems and applications.
Several cost and energy saving solutions for IT infrastructures such as data centers exist today. One solution is to employ Energy Star or Advanced Configuration and Power Interface (ACPI) compliant devices in a data center. These devices are capable of operating indifferent power modes, such as low or standby power modes, whey they are idling or not actively used. However, as silicon fabrication geometries continue to decrease to provide ever smaller electronic devices and spacings there between, even those devices that are in standby power mode continue to draw or consume power through current leakage from nearby powered devices. Consequently, each device must be completely shut down or powered off (e.g., pull the plug) in order to realize maximum power savings.
Another solution involves the use of CPU or memory power throttling techniques to throttle the issue rate of transactions, operations, or throughputs as power or thermal limit thresholds are exceeded. However, such power throttling techniques offer modest power savings because, as noted above, current leakage losses remain. Still another cost saving solution that is supported by many data center vendors is instant capacity on demand. In this solution, customers or users of computing resources are provided with options to dynamically purchase the right to use spare computing resources based on their current demands. While this solution allows a data center customer with cost effective means to increase computing capacity as the workload demand increases, there is really no concept of energy saving because in most cases the spare computing resources reside in data centers and consume power while they wait to be called upon.